#1192: Added failing test for use case.
#1195: Updated anonymous block to named block.
Merge branch 'pass-extends-block-to-mixin' of https://github.com/paulyoung/jade into pass-extends-block-to-mixin
Do mixins block's properly

They are nothing like extends blocks in reality.  It's much easier to
lex, parse and compile them entirely separately
Merge pull request #1224 from visionmedia/pass-extends-block-to-mixin

Pass extends block to mixin